Well-drilling taper tap



-R. E. FAIR. WELL DRILLING TAPER TAP. APPLICATION FILED OCT. 4, I919.

1,335,431. Patented Mar. 30,1920,

* UNIT s'rarns earner RALPH EMERSON FAIR, 0F GHA'ITANQOGA, ASSIGNOR TOLUGEY MANU- FACTURING CORPORATION OF, TENIGESSEE, 0F OHATTANGOGA,TENNESSEE, A COR- POEATION OF TENNESSEE.

W'ELL-DRILLENG TAPER TAP.

To all whom it may concern:

Be it known that I, RALPH E. FAIR, a citizen oi the United States,residing at Chattanooga, in the county of Hamilton and State ofTennessee, have invented certain new and useful Improvements inlVell-Drilling Taper Taps; and I do declare the following to be a full,clear, and exact description of the invention, such as will enableothersskilled in the art to which it appertains to make and usethe same,reference being had to the accompanying drawings, and to the letters andfigures of reference marked thereon, which "form a part of thisspecification.

My invention relates to taper taps designed for use in the art ofwell-drilling for the purpose of engaging and removing from the wellbore a piece of pipe which has become broken ofi' in the at of drillingthe well and left at the bottom of the well. Heretot'ore a piece ofbroken pipe at the bottom of the well has been removed by means of ataper tap screwed into the end of the broken piece of pipe. My inventionhas for its object to improve taper taps of the type mentioned so that abody of water or water and mud may be pumped down through the taper tapand discharged therefrom at a point back from the end of the tap so asto wash away material which may have accumulated in and over the brokenor lost piece of pipe so that the taper tap may then more readily findand enter the end of the broken piece of pipe, and also serve to givenotice to the driller of the engagement of the tap with the broken pipewhich notice will be given by reason of the increased pressure againstwhich the pump will work occasioned by the tap filling the pipe which isto be removed.

To the accomplishment of the foregoing and such other objects as mayhereinafter appear the invention consists in the features hereinafterparticularly described and then sought to be clearly defined by theclaims, reference being had to the accompanying drawing forming a parthereof, and in which 7 Figure l is a side view of the taper tap;

Fig. 2 an end View;

Fig. 3 a longitudinal section of a portion Specificaticn of LettersPatent iiatented Mar. 30, 1926.

Application filed October 4, 1919.

Serial No. 328,451.

of the tap, on an enlarged-scale, showing the threads on a 3 taper perft;

Fig. 4 a longitudinal section on line of Fig. 2, with parts broken away.

In the drawing the tap is illustrated formed at one end with a threadednipple or portion 1 to screw into a length or string of drill pipe bywhich the tap is lowered into the well, and at the other end is formedwith a conical or'tapering point 2 which will enter the end of thebroken or lost piece of pipe that is to be taken out of the well. Thetap tapers longitudinally from end to end and is formed withlongitudinally extending grooves or flutes 3, the body portions of thetaper between the grooves being formed with screw threads The taper perfoot and thenumber 01. threads per inch may vary to suit the conditionsof the work for which the particular tap is designed. In theillustration given in the drawing the taper of the tap for a distance ofapproximately one inch back from the base of the conical point is threeinches per foot, out after the threading has been filiGCJBCl, and fromthat point to the other end of the threaded portion the taper isapproximately three quarters of an inch to the foot, and the threads areout eight to the inch. These proportions however, as stated, may bevaried.

The tap is formed with a central bore 5 extending longitudinally fromthe nipple end that screws into the string of drill pipe to a pointapproximately ten inches, more or less, back from the base of theconical point of the tap, or the lower end of the threaded portion ofthe tap, and from the lower end portion of the bore, two or more holesor ports 6 are bored laterally and at an angle, from the outside of thetap to the interior of the bore, through the fluted portion of the tap.The purpose of the central bore and its lateral discharge ports is toreceive water or fluid from the string of pipe to which the tap isattached and conduct it to a point where, when discharged through thelateral ports, .it will wash away material that may have collected inand over the broken section of pipe that is to be removed so that theconical end of the tap may more readily find and'enter the end of thebroken pipe section so that the screw threads of the tap may, when thetap and string of pipe are rotated, come into threaded attachment to thebroken pipe for the withdrawal of the section from the well.

Another purpose of the central bore and lateral discharge ports to thetap is to give notice to the driller when attachment has been madebetween the tap and broken section of pipe so that he may know when toproceed to withdraw the pipe from the well. This notice is given by theincreased pressure against which the pump that forces the water, or mudand water, through the tap will work the tap enters the. broken piece ofpipe. As the tap is lowered the water 7 escaping from the "lateral portswill find a return through the space between the tap and the wall of thepipe through which it is lowered, and as the tap enters the end of thebroken piece of pipe the space for the flow of the water becomessomewhat restricted so that the pump works against a greater pressure.When the tap has entered the broken section sufficiently for its screwthreads to make attaching engagement with the interior well of thebroken section, and especially so when the ports of the tap have passedwithin the end of the broken section, the flow or discharge of the wateris further restricted, and thedriller knows by the increased pressureagainst which the pump is working that attachment of the tap to thebroken pipe has been effected and that he may proceed to withdraw thetap and at tached broken section of pipe from the well. It will thus-beobserved that an important function is performed in this art by theconstruction of taper tap as described.

I have illustrated and described the preferred details of tapconstruction but it is to be understood that the shape and proportionsmay be changed without departing from the essential features oi theinvention.

Having described my invention and set forth its merits what I claim is:

1. The well drilling tapertap comprising. the longitudii'ially taperingthreaded body formed with a central longitudinal bore provided withlateral fluid discharge ports positioned adjacent the lower threadedportion of the body.

2. The well drilling taper tap comprising the longitudinally taperingthreaded body portion formed with a central longitudinal bore providedwith lateral fluid discharge ports disposed in an angular obliquerelation to the bore and adjacent the lower threaded portion of thebody.

The well drilling taper tap comprising the longitudinally taperingthreaded body portion formed. with longitudinal flutes and a centrallongitudinally extending bore provided with lateral fluid dischargeports through the fluted portion and adjacent the lower threaded portionof the body;

a. The well drilling tap comprising the body portion threaded forattaching engagement with one end of a pipe to be lifted from a well andformed with a central longitudinally extending bore provided with alateral fluid discharge port adjacent one end to clear material from theend of the section of pipe to be removed and indicate to the drillerwhen attachment between the tap and pine section has been made.

In testimony whereof I afliX my signature in presence of two witnesses.

RALPH EMERSON FAIR.

Witnesses:

J. B. WVnLLs, H. L. THATCHER.

